Carburetor



Oct. 31, 1961 Filed March 15, 1960 2 Sheets-Sheet 1 TIE-1 1; IN VEN TOR.

'q wr/iMA/A zfk Oct. 31, 1961 A. H. WINKLER CARBURETOR 2 Sheets-Sheet 2 Filed March 15, 1960 INVENTOR. 5 AME/WM Mlvnzfi United States Patent 3,006,621 CARBURETOR Albert H. Winkler, Elmira, N.Y., assignor to The Bendix Corporation, a corporation of Delaware Filed Mar. 15, 1960, Ser. No. 15,085 4 Claims. (Cl. 261-69) The present invention relates to carburetors and more particularly to antipercolating means for carburetors.

In carburetors as presently constructed, it frequently happens that after the engine has been operated for a time and is then stopped, the carburetor body reaches a temperature high enough to cause boiling of the gasoline or other fuel in the carburetor. This involves the formation of bubbles of fuel vapor below the fuel level, in and around the fuel channels and discharge jet, and these bubbles tend to rise and escape out of the jet, carrying with them quantities of liquid which are discharged into the induction passage. This phenomenon is commonly referred to as percolation and may prevent a stopped engine from starting. In addition to its undesirable affect on the operation of the engine, percolation is also undesirable as being wasteful of fuel and as causing dilution of the engine lubricating oils.

The instant invention avoids these difliculties by utilizing the bubbles to create a vapor lock to prevent or reduce further flow through the channels subject to percolation.

The invention will be readily understood from a reading of the following description taken in connection with the appended drawings wherein:

FIGURE 1 is a top view of a carburetor embodying the present invention;

FIGURE 2 is a sectional view taken along line 2-2 of FIGURE 1; and

FIGURE 3 is a sectional view taken along line 3-3 of FIGURE 1.

Referring now to the drawings numeral designates a carburetor having an induction passage 12 with a choke valve 14 and a throttle 16 mounted therein. A fuel bow-l 18 contains a float 20 which controls a needle valve 22 for maintaining a predetermined fuel level in the bowl. Fuel is discharged from bowl 18 through metering restriction 23 and the main discharge jet 24 into the throat of venturi 26 disposed in induction passage 12. Fuel is also discharged into the induction passage through an idle system, a portion of which is shown at 28.

Auxiliary fuel is discharged from the fuel bowl through economizer valve 30, conduit 32, well 34, tube 36 and calibrated restriction 38 to the main jet 24 downstream of metering restriction 23. An economizer piston 40 is urged downwardly by a spring 42 to open valve 30 and is urged upwardly by the pressure differential between the induction passage pressure downstream of the throttle communicated to one side of piston 40 by a conduit 44 and the float chamber pressure, which may be substantially atmospheric pressure, acting on the other face of the piston.

The well 34 is inclined upwardly and is disposed with its bottom or closed end 46 below the bottom of the fuel bowl 18. The tube 36 is turned over or belied at its upper end and secured to the upper end of well 34 as by a pressed fit. The securing of tube 36 to the walls of well 34 seals the upper end of the well so that the only flow from the well must take place through the interior of tube 36 which at its lower end is spaced from the bottom of the well. The channel or conduit 32 opens into well 34 intermediate the ends of tube 36.

In operation of the device described thus far boiling of the fuel is most likely to occur in the economizer system which being located near the bottom of the carburetor is exposed to the greatest engine heat. With the engine stopped, the spring 42 is eflective to open the economizer valve 30 so that fuel from bowl 18 may flow into the economizer conduit 32 and but for my invention could percolate therefrom into the discharge jet and thence into the induction passage. However, with my invention percolation is stopped or substantially reduced soon after boiling commences through the provision of well 34 and tube 36. When boiling occurs, the light ends or low boiling point constituents of the fuel vaporize in well 34 and a portion of the vapor may escape through tube 36. The remaining liquid fuel in well 34 consisting of the higher boiling point constituents is suflicient to fill the well to a point above the lower end of tube 36. Vapor in tube 36 acting on the top of the liquid column in the tube together with the weight of the liquid in the well act in opposition to further flow of vapor from channel 32 and thus creates a vapor lock in well 34 whereby percolation from the system is stopped.

Tube 36 may be perforated along its side walls to increase the flow capacity of the economizer or power system providing that the individual perforations are small enough to prevent or restrain the bubbles from passing therethrough.

While the well and tube arrangement of the present invention has been described in conjunction with an economizer or power system it may also be used in other systems or fuel channels to stop or reduce percolation therethrough. It is also to be understood that various other arrangements of parts may be made without departing from the scope of the invention.

I claim:

1. In a carburetor, an induction passage, a fuel bowl, a fuel discharge jet connecting said fuel bowl to said induction passage, a metering restriction in said jet, a fuel well connected at one end to said jet downstream of said restriction, a tube in said well spaced from the side walls of said well, means sealing the space between said tube and said well at said one end of said well, a conduit connecting said well intermediate the ends of said tube with said fuel bowl, and valve means responsive to an engine operating condition for controlling the flow through said conduit.

2. In a carburetor, an induction passage, a discharge jet opening into said induction passage, a fuel reservoir, an upwardly extending well formed in said carbuertor, said well communicating at its upper end with said jet and being closed at its lower end, a tube concentrically disposed in said well, said tube being in sealing engagement at its upper end with the walls of said well the remainder of said tube being spaced from the walls and closed end of said well, and conduit means connecting said well intermediate the portion traversed by said tube with said fuel reservoir.

3. In a carburetor, an induction passage, :1 fuel reservoir, a discharge jet connecting said reservoir below the normal fuel level with said induction passage, a metering restriction in said jet, a chamber formed in said carburetor, a tube in said chamber, said tube being secured 3 at one end to the walls of said chamber and the remainder of said tube being spaced from said chamber walls, means connecting said tube to said jet downstream of said restriction, conduit means connecting said reservoir to said chamber intermediate the ends of said tube and valve means responsive to an engine operating condition for controlling the flow through said conduit means.

4. In a carburetor, an induction passage, a fuel reservoir, a fuel discharge jet opening into said induction passage, inner and outer concentrically arranged fuel 10 passages, said fuel passages being joined at one end to 4 permit fuel flow only through the inner passage, means connecting said inner passage to said jet, said inner passage being spaced from the end of the outer passage opposite to the end joined to said inner passage, and means connecting said reservoir to said outer fuel passage intermediate the ends of said inner fuel passage.

2,736,540 Dorl'and Feb. 28, 1956 

